Our freedom, our prosperity, our luxury, they all result from fossil fuels. Ours are the most fortunate generations that have ever lived. Ours are also the most fortunate generations that ever will.

Now we've heard something about the sort of cuts people would like to see. I'm not interested in the cuts that people would like to see. I'm interested in the cuts that science tells us are necessary. And those cuts do not equate to 20% of our current carbon use by 2020. They do not equate to 60% of our current carbon use by 2060. No-one will thank me for saying this but the science is now unequivocal. We need a 90% cut by 2030. That is the only way we have of preventing this whole thing, this whole edifice balanced on a ball, from crashing down around us. And the reason for that is clear.

If we do not cut carbon by 90% by 2030 then carbon emissions in the atmosphere reach 430 parts per million, and that is the point at which unequivocally, most of the world's major ecosystems go into positive feedback. The biosphere becomes a net source of carbon dioxide, and then the game is out of our hands. It has got nothing to do with us any more, because there's no The thing we can do to stop it. The ecosystems on which we have relied to absorb carbon dioxide, they start producing it.

We have twenty five years, ladies and gentlement, in which to act, and not just act a little bit. We have twenty five years in which to cut carbon emissions throughout our economy, the developed world economy, by 90%.

Now there are some people who believe that this can be done, by replacing the fossil fuels on which this great tottering pile has been built, entirely on ambient sources of energy. And that, I am afraid, is in the realms of science fiction. The only way in which the sort of cuts that I am talking about can be brought about, is through a massive cut in the amount of energy we use.

We are talking not jut about changing the fact that we fly off to Seville for 39 quid for a weekend. We are talking about changing the very basis of the way in which you and I, and all of us live.

If this problem could be solved by slagging off George Bush, we would have solved it by now, but the problem does not stop with him. The problem does not stop with the US. The problem does not stop with our own government. The problem does not stop with those other people who go flying, and driving, and leaving their windows open while their heating is on. The problem also stops with every one of us.

This unique historical fight, this unique historical moment, an interlude between economical constraint and ecological catastrophe, this interlude in which the most fortunate generations ever, live, requires a most extraordinary effort of confronting everything.

I just want to leave you with this one thought. We are not just fighting against George Bush, but we are fighting against George Bush. We are not just fighting against the United States but we are fighting against the United States. We are not just fighting against Tony Blair, but we are fighting against Tony Blair. But the biggest fight of all in which we are engaged, is not a fight against the US, Tony Blair, or anyone else. It is a fight against what we have become. It is a fight against our own inherent tendencies to desire and consume and grab more and more and more. The biggest fight of our lives, ladies and gentlemen, the biggest fight of our lives is not out there, it is in here (pointing to his head).